add UT for MetaLocationCache

hbase-server/src/main/java/org/apache/hadoop/hbase/master/MetaLocationCache.java

@@ -62,7 +62,8 @@ class MetaLocationCache implements Stoppable {
   @VisibleForTesting
   static final int DEFAULT_SYNC_INTERVAL_SECONDS = 1;
 
-  private static final String FETCH_TIMEOUT_MS =
+  @VisibleForTesting
+  static final String FETCH_TIMEOUT_MS =
     "hbase.master.meta-location-cache.fetch-timeout-ms";
 
   // default timeout 1 second

hbase-server/src/test/java/org/apache/hadoop/hbase/master/TestMetaLocationCache.java

@@ -0,0 +1,112 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.apache.hadoop.hbase.master;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertTrue;
+import static org.mockito.ArgumentMatchers.anyInt;
+import static org.mockito.Mockito.mock;
+import static org.mockito.Mockito.when;
+
+import java.util.Arrays;
+import java.util.List;
+import java.util.concurrent.CompletableFuture;
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.hbase.ChoreService;
+import org.apache.hadoop.hbase.HBaseClassTestRule;
+import org.apache.hadoop.hbase.HBaseConfiguration;
+import org.apache.hadoop.hbase.HRegionLocation;
+import org.apache.hadoop.hbase.ServerName;
+import org.apache.hadoop.hbase.TableName;
+import org.apache.hadoop.hbase.client.AsyncClusterConnection;
+import org.apache.hadoop.hbase.client.RegionInfoBuilder;
+import org.apache.hadoop.hbase.testclassification.MasterTests;
+import org.apache.hadoop.hbase.testclassification.MediumTests;
+import org.apache.hadoop.hbase.util.FutureUtils;
+import org.junit.After;
+import org.junit.AfterClass;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import org.junit.ClassRule;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+
+@Category({ MasterTests.class, MediumTests.class })
+public class TestMetaLocationCache {
+
+  @ClassRule
+  public static final HBaseClassTestRule CLASS_RULE =
+    HBaseClassTestRule.forClass(TestMetaFixerNoCluster.class);
+
+  private static Configuration CONF = HBaseConfiguration.create();
+
+  private static ChoreService CHORE_SERVICE;
+
+  private static int FETCH_TIMEOUT_MS = 100;
+
+  private MasterServices master;
+
+  private MetaLocationCache cache;
+
+  @BeforeClass
+  public static void setUpBeforeClass() {
+    CONF.setInt(MetaLocationCache.SYNC_INTERVAL_SECONDS, 1);
+    CONF.setInt(MetaLocationCache.FETCH_TIMEOUT_MS, FETCH_TIMEOUT_MS);
+    CHORE_SERVICE = new ChoreService("TestMetaLocationCache");
+  }
+
+  @AfterClass
+  public static void tearDownAfterClass() {
+    CHORE_SERVICE.shutdown();
+  }
+
+  @Before
+  public void setUp() {
+    master = mock(MasterServices.class);
+    when(master.getConfiguration()).thenReturn(CONF);
+    when(master.getChoreService()).thenReturn(CHORE_SERVICE);
+    cache = new MetaLocationCache(master);
+  }
+
+  @After
+  public void tearDown() {
+    if (cache != null) {
+      cache.stop("test end");
+    }
+  }
+
+  @Test
+  public void testError() throws InterruptedException {
+    AsyncClusterConnection conn = mock(AsyncClusterConnection.class);
+    when(conn.getAllMetaRegionLocations(anyInt()))
+      .thenReturn(FutureUtils.failedFuture(new RuntimeException("inject error")));
+    when(master.getAsyncClusterConnection()).thenReturn(conn);
+    Thread.sleep(2000);
+    assertTrue(cache.getAllMetaRegionLocations(true).isEmpty());
+
+    HRegionLocation loc =
+      new HRegionLocation(RegionInfoBuilder.newBuilder(TableName.META_TABLE_NAME).build(),
+        ServerName.valueOf("localhost", 12345, System.currentTimeMillis()));
+    when(conn.getAllMetaRegionLocations(anyInt()))
+      .thenReturn(CompletableFuture.completedFuture(Arrays.asList(loc)));
+    Thread.sleep(2000);
+    List<HRegionLocation> list = cache.getAllMetaRegionLocations(false);
+    assertEquals(1, list.size());
+    assertEquals(loc, list.get(0));
+  }
+}